Effects of vortex flaps on the low-speed aerodynamic characteristics of an arrow wing

Tests were conducted in the Langley 12-foot low-speed wind-tunnel to determine the longitudinal and lateral-directional aerodynamic effects of plain and tabbed vortex flaps on a flat-plate, highly swept arrow-wing model. Flow-visualization studies were made using a helium-bubble technique. Static forces and moments were measured over an angle-of-attack range from 0 deg to 50deg for sideslip angles of 0 deg and + or - 4 deg

Pressure distribution on a 1- by 3-meter semispan wing at sweep angles from 0 deg to 40 deg in subsonic flow

A 1- by 3-meter semispan wing of taper ratio 1.0 with NACA 0012 airfoil section contours was tested in the Langley V/STOL tunnel to measure the pressure distribution at five sweep angles, 0 deg, 10 deg, 20 deg, 30 deg, and 40 deg, through an angle-of-attack range from -6 deg to 20 deg. The pressure data are presented as plots of pressure coefficients at each static-pressure tap location on the wing. Flow visualization wing-tuft photographs are also presented for a wing of 40 deg sweep. A comparison between theory and experiment using two inviscid theories and a viscous theory shows good agreement for pressure distributions, normal forces, and pitching moments for the wing at 0 deg sweep

Phase diagrams of a p-Wave superconductor inside a mesoscopic disc-shaped sample

We study the finite-size and boundary effects on a time-reversal-symmetry breaking p-wave superconducting state in a mesoscopic disc geometry using Ginzburg-Landau theory. We show that, for a large parameter range, the system exhibits multiple phase transitions. The superconducting transition from the normal state can also be reentrant as a function of external magnetic field.Comment: Revised version published in Physical Review

Signal Transduction Mechanisms for the Stimulation of Lipolysis by Growth Hormone: A Dissertation

The purpose of this study was to investigate the mechanism of action of lipolysis by growth hormone in rat adipocytes. GH-induced lipolysis, in contrast to that of isoproterenol (ISO), is slow in onset (lag time \u3e1h), small in magnitude (~2X basal). and requires corticosteroid. Evidence for direct coupling between GH receptors and adenylyl cyclase or G-proteins is lacking, and although we could detect no measurable change in cAMP content after treatment with GH + dexamethasone (Dex), it is likely that cAMP activation of protein kinase A is a central event in GH-induced lipolysis. Rp-cAMPS, a competitive antagonist of cAMP was equally effective in decreasing lipolysis in tissues treated with GH/Dex or a comparably lipolytic dose of ISO. Incorporation of 32P from γ-32P-ATP into kemptide, a synthetic oligopeptide substrate for protein kinase A, was increased in homogenates of GH/Dex-treated tissue. This increase was correlated with increased lipolysis. Earlier estimates based upon 32P-ribosylation of Gi catalysed by pertussis toxin (PTx) suggested that the abundance of Gi in adipocyte membranes was decreased 4h after treatment of hypophysectomized rats with GH. We therefore examined the possibility that changes in amount or distribution of G-proteins in adipocyte membranes might account for the lipolytic action of GH. Homogenates of GH/Dex-treated and control adipocytes were subjected to differential centrifugation and the abundance of G-proteins in low speed, l6k x g (16k), pellets and high speed, 100k x g (100k), pellets were determined by quantitative Western analysis with densitometry. A 35% loss of Giα2 from the l6k pellet compared from tissues treated with GH/Dex was associated with a 70% increase of Giα2 in the 100k pellet. No change in Gsα was observed in the l6k pellet but a 35% loss of Gsα was seen in the 100k pellet. The G proteins in the l6k pellet were fractionated on a continuous sucrose gradient followed by quantitation with Western analysis or autoradiography after 32P-NAD ribosylation. Giα2 was consistently shifted from heavier to lighter fractions of the l6k pellet after treatment with GH/Dex. Similar shifts of Gsα were not seen. The distribution of 32P-labelled proteins was comparably altered after incubation of homogenates of control and GH/Dex treated adipocytes with PTx and 32P-NAD. These shifts were blocked by treatment of adipocytes with 100μM colchicine which also blocked the lipolytic action of GH/Dex. We propose that an action of GH/Dex on the cytoskeleton of fat cells may change the cellular distribution of G-proteins in a manner that produces a relative decrease in the tonic inhibitory influence of Gi on adenylyl cyclase

Comparison of aerodynamic theory and experiment for jet-flap wings

Aerodynamic theory predictions made for a jet flapped wing were compared with experimental data obtained in a fairly extensive series of tests in the Langley V/STOL tunnel. The tests were made on a straight, rectangular wing and investigated two types of jet flap concepts: a pure jet flap with high jet deflection and a wing with blowing at the knee of a plain trailing edge flap. The tests investigated full and partial span blowing for wing aspect ratios of 8.0 and 5.5 and momentum coefficients from 0 to about 4. The total lift, drag, and pitching moment coefficients predicted by the theory were in excellent agreement with experimental values for the pure jet flap, even with the high jet deflection. The pressure coefficients on the wing, and hence the circulation lift coefficients, were underpredicted, however, because of the linearizing assumptions of the planar theory. The lift, drag, and pitching moment coefficients, as well as pressure coefficients, were underpredicted for the wing with blowing over the flap because of the failure of the theory to account for the interaction effect of the high velocity jet passing over the flap

Inert-states of spin-5 and spin-6 Bose-Einstein condensates

In this paper we consider spinor Bose-Einstein condensates with spin f=5 and f=6 in the presence and absence of external magnetic field at the mean field level. We calculate all of so-called inert-states of these systems. Inert-states are very unique class of stationary states because they remain stationary while Hamiltonian parameters change. Their existence comes from Michel's theorem. For illustration of symmetry properties of the inert-states we use method that allows classification of the systems as a polyhedron with 2f vertices proposed by R. Barnett et al., Phys. Rev. Lett. 97, 180412 (2006).Comment: 19 pages, 4 figure

Symmetry and inert states of spin Bose Condensates

We construct the list of all possible inert states of spin Bose condensates for $S \le 4$. In doing so, we also obtain their symmetry properties. These results are applied to classify line defects of these spin condensates at zero magnetic field.Comment: an error in Sec III C correcte

Sensitivity-analysis method for inverse simulation application

An important criticism of traditional methods of inverse simulation that are based on the Newton–Raphson algorithm is that they suffer from numerical problems. In this paper these problems are discussed and a new method based on sensitivity-analysis theory is developed and evaluated. The Jacobian matrix may be calculated by solving a sensitivity equation and this has advantages over the approximation methods that are usually applied when the derivatives of output variables with respect to inputs cannot be found analytically. The methodology also overcomes problems of input-output redundancy that arise in the traditional approaches to inverse simulation. The sensitivity- analysis approach makes full use of information within the time interval over which key quantities are compared, such as the difference between calculated values and the given ideal maneuver after each integration step. Applications to nonlinear HS125 aircraft and Lynx helicopter models show that, for this sensitivity-analysis method, more stable and accurate results are obtained than from use of the traditional Newton–Raphson approach

Signature of superconducting states in cubic crystal without inversion symmetry

The effects of absence of inversion symmetry on superconducting states are investigated theoretically. In particular we focus on the noncentrosymmetric compounds which have the cubic symmetry $O$ like Li$_2$Pt$_3$B. An appropriate and isotropic spin-orbital interaction is added in the Hamiltonian and it acts like a magnetic monopole in the momentum space. The consequent pairing wavefunction has an additional triplet component in the pseudospin space, and a Zeeman magnetic field $\bf{B}$ can induce a collinear supercurrent $\bf{J}$ with a coefficient $\kappa(T)$. The effects of anisotropy embedded in the cubic symmetry and the nodal superconducting gap function on $\kappa(T)$ are also considered. From the macroscopic perspectives, the pair of mutually induced $\bf{J}$ and magnetization ${\bf{M}}$ can affect the distribution of magnetic field in such noncentrosymmetric superconductors, which is studied through solving the Maxwell equation in the Meissner geometry as well as the case of a single vortex line. In both cases, magnetic fields perpendicular to the external ones emerge as a signature of the broken symmetry.Comment: 16 pages in pre-print forma